1. Field
The present invention relates to a display device preventing a getter layer from contacting elements disposed in the display device.
2. Background
FIG. 1 is a simplified cross-sectional view of an organic light-emitting device of the related art.
As shown in FIG. 1, the organic light-emitting device, one of the display devices, comprises a pixel part disposed on a substrate 1. An anode electrode 2 and a cathode electrode 4, included in the pixel part, are connected with a data line and a scan line, disposed on the outside of the pixel part, respectively. Ends of the data line and the scan line are disposed on at least one edge of the substrate 1, and form a pad part.
And then, the pixel part, the data lines and the scan lines are isolated from the outside by a cap attached to the substrate 1 using a sealant.
Each element included in the organic light-emitting device, particularly an organic light-emitting layer 3 disposed on the anode electrode 2 may be damaged by high temperature and moisture, and thus a cap is attached to the substrate 1 in order to protect the elements of the organic light-emitting device from the outer environment.
However, it is difficult to perfectly prevent moisture and oxygen existing in the outer environment from being transmitted to an inner space of the organic light-emitting device (i.e. a space between the cap and the substrate 1) through microscopic gaps between the cap and the substrate 1 to which the cap is attached.
In order to remove the moisture or the oxygen transmitted to the inner space of the organic light-emitting device, the getter layer is attached to an inner surface of the cap.
The getter layer, composed of chemical materials, absorbs the moisture by chemical reactions with the moisture, whereby the moisture existing in the inner space between the cap and the substrate 1 is removed. Such an absorbing function of the getter layer prevents each element of the organic light-emitting device from being damaged by the moisture.
External force such as vibration, impact, etc., may be exerted on the cap of the organic light-emitting device during many quality tests. In case the external force is exerted on the cap having a thin thickness, the cap is pressed toward the substrate 1.
Also, in order to enlarge a size of the organic light-emitting device, a size of the cap should be increased, and the cap having a thin thickness and a large size experiences deflection by its weight.
Therefore, the getter layer attached to the inner surface of the cap may contact the cathode electrode 4 of the pixel part by deflection induced by the external force or the weight of the cap.
Chemical reaction occurs at a contact area between the getter layer composed of chemical materials and the cathode electrode 4 composed of metal. High chemical activity of the getter layer accelerates the chemical reaction, whereby the cathode electrode 4 is damaged, and even peeled from the substrate 1. The damage of the cathode electrode 4 and the peeling of the cathode electrode 4 have a bad influence on the function of the organic light-emitting device.
In case the cathode electrode 4 composed of metal is peeled, metallic particles are separated from the cathode electrode 4. Such metallic particles are located between the cathode electrodes 4, whereby the cathode electrodes 4 may be shorted by the metallic particles.
Such a problem occurs during transportation, manipulation, and use of the display device as well as during the quality test of the display device.